Finally, here, tonight, finding hope where you least expect it. Parents of an autistic son, so desperate, they turned for help to someone in prison. A prisoner, who makes the most of a second chance. Here's ABC's Steve osunsami. Reporter: We have to say this first. In 1998, Chris Vogt was sentenced to 48 years in a Colorado prison for helping kill a man. I am in prison on a murder case that I'm guilty of. Reporter: But for the families of nine autistic children, this convicted murderer is a savior. For years, they've allowed prisoners here to train service dogs for the blind and deaf. Good boy. Reporter: But prisoner 100765 did something amazing. He read all he could and taught himself to train service dogs for children with autism. You're teaching him. Yeah, that's right, buddy. Reporter: The dogs come from local shelters. He trains inside his cell, acting out problem behaviors himself -- this dog trained to help a child sleep at night. Good boy. Reporter: The parents of 9-year-old Zachary tucker were desperate. He was refusing to be touched. His teacher says he would stop class. He was bawling tears. He would crunch down in the fetal position at his desk. Reporter: So, on weekends, the family sent their son 200 miles to this state prison to work with Mr. Vogt. Prison guards are nearby. Zach's new dog, Clyde, is trained to know when Zach's anxiety is building and gently break his mood. I've been calm enough to socialize with kids, which I haven't been able to do in a long time. Reporter: And when we travelled with Zach and his family to the prison again, what was once unthinkable. Zach gave Chris a hug. This is the thing I get to do that gives back. You know, like Zach, and even older kids. When they come in and work with me, they just see -- you know, they don't see the murderer no more. Reporter: His family says the prison is the last place they thought they would find help. He made a mission out of helping our son. He has proven he can make an incredible difference in people's lives. Reporter: Steve osunsami, ABC news, Colorado Springs.

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